1. Field of the Invention
This invention relates to a disc cartridge having a disc-shaped recording medium, such as a magnetic disc, accommodated therein.
2. Description of Related Art
There has so far been known a disc cartridge having a flexible magnetic disc with a diameter of, for example, 3.5 inch, accommodated therein as a disc-shaped recording medium. This disc cartridge has a main cartridge body portion including a set of shells, that is an upper shell and a lower shell, combined together. These upper and lower shells are formed of a resin material, and are provided with recording and/or reproducing apertures for exposing a portion of the flexible magnetic disc to outside across its inner and outer rims. On the main cartridge body portion is mounted a shutter member for opening/closing the recording and/or reproducing apertures.
In the conventional disc cartridge of the above-described type, a shutter member is moved on loading the disc cartridge in a recording and/or reproducing apparatus so that its recording and/or reproducing aperture is opened. As the flexible magnetic disc is run in rotation, the information is recorded and/or reproduced by a magnetic head intruded through the recording and/or reproducing aperture.
Recently, in a portable electronic equipment, such as a portable computer or a digital still camera, a demand is raised for a recording and/or reproducing apparatus that is able to handle the information of a larger volume, and for a information recording medium used for this recording and/or reproducing apparatus.
As for an information recording medium, used for this sort of the recording and/or reproducing apparatus, it is proposed to reduce the size or thickness of a disc cartridge having the flexible magnetic disc housed therein.
Meanwhile, the upper and lower shells may be formed of a metallic material to reduce the thickness and hence the size of the main cartridge body unit.
However, as the disc cartridge is reduced in size and thickness, the recording and/or reproducing apparatus, on which is loaded the disc cartridge, is also reduced in size and thickness. Thus, with this recording and/or reproducing apparatus, the cartridge inserting/ejecting opening, through which the disc cartridge is inserted and ejected, is of an extremely small size, with the result that a gap between the outer periphery of the disc cartridge and the inner periphery of the cartridge inserting/ejecting opening (play) is of an extremely small value. Also, in this recording and/or reproducing apparatus, there is provided a door adapted for being rotated to open/close the cartridge inserting/ejecting opening to prevent intrusion of contaminants through the cartridge inserting/ejecting opening. When the disc cartridge is inserted into the recording and/or reproducing apparatus, this door slides on the major surface of the main cartridge body unit so as to be rotated towards the inside of the apparatus.
That is, the disc cartridge, reduced in size and thickness, has a drawback that it abuts on the cartridge inserting/ejecting opening when inserted into or ejected from the recording and/or reproducing apparatus, or the door sliding on the major surface of the main cartridge body unit destructs the shutter member arranged outside the main cartridge body unit when the disc cartridge is ejected from the apparatus.
It is therefore an object of the present invention to provide a disc cartridge in which a shutter member may be positively prevented from being destroyed and in which the main cartridge body unit can be reduced in size and thickness.
For accomplishing this object, the present invention provides a disc cartridge including a disc-shaped recording medium, a main cartridge body unit including an upper plate and a lower plate, both of a metal material, forming a plate pair, and an intermediate frame, sandwiched between the upper and lower plates, and an intermediate frame, recording and/or reproducing apertures formed in the main cartridge body unit for exposing a portion of a recording area of the disc-shaped recording medium to outside across the inner and outer rims of the disc-shaped recording medium, and a shutter member provided for linear movement within the inside of the main cartridge body unit for opening/closing the recording and/or reproducing aperture. The intermediate frame is sandwiched between the upper and lower plates. The disc-shaped recording medium is housed in the main cartridge body unit.
With the present disc cartridge, in which the shutter member is provided inwardly of the main cartridge body unit, it is possible to prevent load application from to the shutter member from outwardly of the main cartridge body unit.
With the present disc cartridge, it is also possible to prevent destruction of the shutter member and to reduce the thickness and size of the main cartridge body unit.